Re: [RFC PATCH 2/2] arm64: Use SYSTEM_OFF2 PSCI call to power off for hibernate

From: Sudeep Holla <sudeep.holla@arm.com>
To: David Woodhouse <dwmw2@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org,
	Paolo Bonzini <pbonzini@redhat.com>,
	Sudeep Holla <sudeep.holla@arm.com>,
	Jonathan Corbet <corbet@lwn.net>, Marc Zyngier <maz@kernel.org>,
	Oliver Upton <oliver.upton@linux.dev>,
	James Morse <james.morse@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Zenghui Yu <yuzenghui@huawei.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Lorenzo Pieralisi <lpieralisi@kernel.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Len Brown <len.brown@intel.com>, Pavel Machek <pavel@ucw.cz>,
	Mostafa Saleh <smostafa@google.com>,
	Jean-Philippe Brucker <jean-philippe@linaro.org>,
	linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
	kvmarm@lists.linux.dev, linux-pm@vger.kernel.org
Subject: Re: [RFC PATCH 2/2] arm64: Use SYSTEM_OFF2 PSCI call to power off for hibernate
Date: Thu, 14 Mar 2024 11:09:11 +0000	[thread overview]
Message-ID: <ZfLa1_TWArT7tCtb@bogus> (raw)
In-Reply-To: <ZfHHlBgSNr8Qm22D@bogus>

On Wed, Mar 13, 2024 at 03:34:44PM +0000, Sudeep Holla wrote:
> On Tue, Mar 12, 2024 at 04:36:05PM +0000, David Woodhouse wrote:
> > On Tue, 2024-03-12 at 15:57 +0000, Sudeep Holla wrote:
> > > Looked briefly at register_sys_off_handler and it should be OK to call
> > > it from psci_init_system_off2() below. Any particular reason for having
> > > separate initcall to do this ? We can even eliminate the need for
> > > psci_init_system_off2 if it can be called from there. What am I missing ?
> >
> > My first attempt did that. I don't think we can kmalloc that early:
> >
>
> That was was initial guess. But a quick hack on my setup and running it on
> the FVP model didn't complain. I think either I messed up or something else
> wrong, I must check on some h/w. Anyways sorry for the noise and thanks for
> the response.
>

OK, it was indeed giving -ENOMEM which in my hack didn't get propogated
properly 🙁. I assume you have some configs that is resulting in the
crash instead of -ENOMEM as I see in my setup(FVP as well as hardware).

Sorry for the noise.

--
Regards,
Sudeep